Attachment plug



H. CATLIN ATTACHMENT PLUG Fil d March 26. 1920 INVENTOR.

How T Can m ATTORN EYS Patented Dec. 2, 1924.

UNITED STATES PATENT OFFICE.

HOYT CATLIN, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE BRYANT ELECTRICCOMPANY, OF BRIDGEIORT, CONNECTICUT, A CORPORATION OF CONNECTICUT.

ATTACHMENT PLUG.

Appllication filed March 26, 1920-.

'1 all whom it may concern:

Be it known that I, I-IoY'r GATLIN, a citizen of the United States ofAmerica, residing at Bridgeport, in the county of F airfield and Stateof Connecticut, have invented certain new and useful Improvements in Attachment Plugs, of which the following is a specification.

My invention relates to attachment plugs, and particularly toattachmentplugs of the Edison type, the object of my invention being toprovide an efficient plug of economical construction, hereinafterdescribed or shown in the accompanying drawings, in which- Fig. l isaside elevation of a plug in which my invention is embodied in one form;

Fig. 2 is a section on the line 2-2, Fig. 3;

Fig. 3 is a section on the line 3-3, Fig. 2;

Fig. 4 is a section on the line 1- 1:, Fig. 2; and

Fig. 5 is a dropped perspective of the outer insulating button or bodyofthe plug with the metal parts detached.

The plug as here shown comprises a pair of insulating pieces 6 and 7,the piece 6 comprising a block provided with an annular flange affordinga finger hold and a shoulder 9 forming an annular seat against which thescrew shell side contact 10 of the plug bears. The insulating piece 7 isa relatively small button, to the periphery of which the screw shell 10is crimped at 11. This button is also centrally perforated to receive acenter contact rivet 12, the inner end of which is spread in the well 13formed in the inner face of the button. A center contact screw 14passing through the rivet detachably engages the offset foot of astandard 15.

The standard 15 is integral with a terminal plate 16 tapped to receivebinding screw 17, by which one of the wire leads is secured andelectrically connected to the center contact of the plug. The standardis also tapped at 18 to receive a screw bolt 19 passing through theblock 6 and serving to hold the terminal plate and standard permanentlysecured thereto. The head of the screw bolt 19 is located in a well inthe outer end of the block 6, and is rendered inaccessible as well asinsulated by wax 20 flowed into the well. A second terminal plate 21,sim- Serial No. 368,953.

ilarly secured, is seated on a ledge 22 formed on the inner face of theblock 6 and communicating wtih a lateral recess 23. Into this lateralrecess projects a spring tongue 21, which extends outward intofrictional contact with the screw shell 10 and thus establisheselectrical connection therewith. The binding screw 25, carried by theterminal plate 21, affords means for connecting the other leading-inwire.

Between the ledge 22, in which the terminal plate 21 is seated, and thecorresponding ledge 26, on which the plate 16 is seated, the block 6 isrecessed to afford a chamber 27, in which is accommodated a strainrelief knot 28 tied in the exposed ends of the wires embedded in thecable 29. Strain on the binding screw connections 17 and 25 is thuseliminated. The passage for the cable opens cent-rally to the strainrelief knot chamber 27 on opposite sides of which the ledges 22 and 26are located.

To Wire the attachment plug it is merely necessary to loosen the centercontact screw 14, thus freeing the standard 15 and permitting the button7, with the screw shell 10 carried thereby, to be separated from theblock 6 carrying the wire terminals. The wires for the cable 29havingbeen exposed, and their. ends bared and secured tothe binding screws 17and 25, it is merely necessary to readjust the button 7, sleeving theouter end of the screw shell upon the button, until it is seated againstthe shoulder 9. The frictional engagement between the spring plate 24and the screw shell establishes electrical connection between theterminal plate 21 and the shell, While the reinsertion of the screw 14not only secures the parts in assembled position, but also establisheselectrical connection with the other terminal plate 16. swiveling of thescrew shell With relation to the block 6 is prevented by a lug 31projecting downward from the shoulder 9 into a corresponding notch 32formed in the outer edge of the screw shell.

Various modifications in detail of construction will readily occur tothose skilled in the art, which do not depart from what I claim as myinvention.

I claim- In an attachment plug, an insulating button forming a fingergrip externally shouldered to afford a non-rotating abutting engagementWith a screw shell freely, sleeved over one end of the button, saidbutton being pierced to afl'ord an entry channel and strain relief knotchamber for a Wire cable, countersunk ledges formed in the inner face ofsaid button and extending substantially at right angles to the axis ofthe plug and on opposite sides of said strain relief chamber, Wireterminal plates seated on said ledges, means carried by the button forsecuring said terminal plates on said ledges, said button being recessedbeneath said plates to form Wells, binding screws passing through saidplates into said Wells, a laterally projecting ofi'set lug from one ofsaid plates adapted to frictionally engage the screw shell sleeved uponthe button, a lug projecting from the other terminal plate toward theentering end of the plug and having an oil'- set free end tapped toreceive a securing screw, together with an insulating disc at theentering end for the plug, a screw shell carried thereby, and a centercontact screw passing through the disc and engaging the tapped free endof said offset terniinal lug, to hold the plug contacts assembled and inelectrical connection with the conductors on the button.

In testimony whereof I have signed my name to this specificatioi'i.

HOYT UATLIN.

